Analysis setting for running large models

AmirMar
AmirMar Altair Community Member
edited March 2021 in Community Q&A

Dear Forum,

I try to run a problem which has several hundreds of thousands quadratic elements using the Lanczos solver.
I tried to submit using SMP and 8 cpus. I only asked for 20 first eigenmodes.
After 60 minutes I gave up and aborted the job.
With another solver, using equivalent setup, I received results after less than 10 minutes.
I'm sure that I can have faster results using command line arguments.

Does anybody have some experience with a similar problem?

Thank you,
Amir

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Answers

  • Adriano Koga_20259
    Adriano Koga_20259 New Altair Community Member
    edited March 2021

    For large models, with thousands/millions of DOFs you would greatly benefit from using AMSES modal solver in OptiStruct.

    For activating it, change the EIGRL(lanczos) to EIGRA(amses).

    Make sure you have enough RAM and disk space, anyway.

  • AmirMar
    AmirMar Altair Community Member
    edited March 2021

    Hello Adriano and thank you for the answer.

    I understand that the lanczos solver may not be preferrable over amses.

    However I would like to understand how best to submit my jobs and I expect to have similar runtimes to the competitor solver.

    I tried to use -ddm but I didn't see any improvement. I see however that the executables writes vigorously to the hard drive. I'm not sure that the memory setting is therefore optimized.

    Is there any recommendation in this respect?

    Thank you,

    Amir

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